This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (45) Citing Articles via Google Scholar Google Scholar Articles by Sakri, F. A. K. Articles by Shannon, J. C. Search for Related Content PubMed PubMed Citation Articles by Sakri, F. A. K. Articles by Shannon, J. C. Agricola Articles by Sakri, F. A. K. Articles by Shannon, J. C.

Articles

Movement of ¹⁴C-labeled Sugars into Kernels of Wheat (Triticum aestivum L.) ¹

Jack C. Shannon^b,3

^a Department of Agronomy, Purdue University, West Lafayette, Indiana, 47907, Plant Science Research Division, Agricultural Research Service, United States Department of Agriculture and Department of Agronomy, Purdue University, West Lafayette, Indiana, 47907

An anatomical study of wheat (Triticum aestivum L.) kernels 14 days after anthesis revealed that the tracheary elements of the pericarp vascular bundle are not in direct continuity with those of the rachilla. The phloem was continuous from the rachilla into the crease of the pericarp.

Shortly after exposure of the flag leaf to ¹⁴CO₂, relatively high proportion of the ¹⁴C extracted from the pericarp and endosperm was found in glucose and fructose. With additional time, the percentage of ¹⁴C in the monosaccharides declined and that in sucrose increased to a maximum 3 hours after ¹⁴CO₂ exposure. The monosaccharides comprised about one-half of the soluble sugars extracted from the pericarp. Based on these observations, it appeared that sucrose hydrolysis might be prerequisite to sugar movement from the terminal phloem elements in the pericarp and into the endosperm. However, when ¹⁴C-fructosyl-sucrose was injected into the peduncle, there was little additional randomization of the ¹⁴C between the glucose and fructose moieties of sucrose extracted from the pericarp and endosperm compared to the rachis sucrose. If we assume that injected sucose was transported to the kernels via the phloem, then either sucrose moves out of the terminal phloem elements in the pericarp and into the endosperm unaltered, or if hydrolysis and resynthesis are a prerequisite to transport into the endosperm, the products of hydrolysis are not freely available for isomerization.

³ Present address: Department of Horticulture, The Pennsylvania State University, University Park, Pa. 16802.

¹ Cooperative investigations of the Plant Science Research Division, Agricultural Research Service, United States Department of Agriculture, and the Indiana Agricultural Experiment Station. Journal Paper No. 5638.

This article has been cited by other articles:

				S. R. Larson, J.N. Rutger, K. A. Young, and V. Raboy Isolation and Genetic Mapping of a Non-Lethal Rice (Oryza sativa L.) low phytic acid 1 Mutation Crop Sci., September 1, 2000; 40(5): 1397 - 1405. [Abstract] [Full Text]

				T. Nakamura, P. Vrinten, K. Hayakawa, and J. Ikeda Characterization of a Granule-Bound Starch Synthase Isoform Found in the Pericarp of Wheat Plant Physiology, October 1, 1998; 118(2): 451 - 459. [Abstract] [Full Text]